Mixing apparatus



Oct. 14, 1930. B. G. KLUGH MIXING APPARATUS 4 .Sheet .--Sheet 1 FiledJune 14, 1926 Oct. 14, 1930. B. G. KLUGH MIXING APPARATUS 4 Sheets-Sheet2 Filed June 14, 1926 Oct. 14, 1930. B. G. KLUGH MIXING APPARATUS FiledJun 14, 1926 4 Sheet-Sheet 5 qml fiesses waif Oct. 14, 1930. a. G. KLUGHMIXING APPARATUS Filed June 1926 4 Sheets-Sheet 4 01" ngy advantage,particularly where materials of Patented Oct. 14, 1930 UNITED STATESPATENT OFFICE BETHUNE G. KLUGH, OE CHICAGO, ILLINOIS, ASSIGNOR TOAMERICAN ORE RECLAMA- TION COMPANY, OF NEW. YORK, N. Y., A CORPORATIONOF NEW YORK mxme arrana'ros' Application filed June 14} ized ores forsintering. While the machine has been developed primarily for thisspecific field, nevertheless it will be understood that thecharacteristic features and mode of operation of the machine can beemployed in other types of mixing apparatus with equal the fineness andconsistency of these sintering ores are to be handled.

In preparing ores. for sintering, it is necessary that the water addedto the ore be accurately proportioned and intimately mixed with the ore,so that the resulting mixture will be substantially homogeneous incharacter. When handling ores of certain characteristics, particularlythose of plastic nature and of extreme fineness, this mixing operationpresents numerous dilficulties. This can best be illustrated byconsidering the types of machines which have been employed heretoforefor performing this mixing operation. These prior machines may begenerally classified as: (l) the cylindrical type, known as drum or tubemixers; and (2) the trough type in which rotates one or more blades,this being reI'erred to as the pug-mill type. In the case of extremelyplastic ores, the cylidrical mixer does not perform satisfactorily, asthe ore, when moistened to that degree required for sintering, tends toagglomerate into large masses or balls in this type of mixer, whichaction either prevents intimate mixing of the constituents of thesintering charge, or prevents thorough admixture of the water therewith.Furthermore, in this type of mixer, as heretofore constructed, the oretends to adhere to the inner walls of the cylinder and to build up insuccessive strata on these walls.

These extremely plastic ores also introduce difiiculties in theoperation of the pug-mil] type of mixing machine. Such ores tend to packhard in the trough below the peripheral path of the blades, and thisincrusted mass produces a braking retardation on the blades,necessitating a greater expenditure of power 1926. Serial No. 115,768.

and also resulting in rapid wearing of the blades.

With a view to overcoming the difficulties inherent in both these priortypes of mixers, I have developed the present type of mixer, utilizingcertain characteristics of each of these prior types, but avoiding theobjections inherent therein. More particularly, I employ a blade actionin combination with a r0- tating cylinder, the cylinder operating in themanner of a rotating trough for constantly feeding the material to theaction of the blades, the cylinder and blades thus cooperating to theend of intimately mixing the material, without giving the material anyopportunity to adhere and harden on the inner walls of the cylinder.

A further feature of my invention pertains to improved means forbal1ing'the mixture after the ore has been passed through the mixingapparatus and has been brought to the proper consistency for thisballing away to illustrate the relation of the mix ing blades;

Fig. 2 is a transverse sectional view taken on the irregular sectionalplane of the line 22 of Fig. 1;

Fig. 3 is a side view of the machine illustrating the cylinder inlongitudinal section;

Fig. 4 is a detail view of one of the blade units;

Fig. 5 is a side elevational View, somewhat diagrammatic in character,illustrating my improved mixing apparatus having associated therewith aballing cone for balling the ore after the mixing thereof;

Fig. 6 is a similar view illustrating a balling cone which iscontiguously joined to the mixing cylinder;

Fig. 7 is a side view of another embodiment embodiment and Fig. 9 is atransverse sectional view through one of the balling cones, illustratinga polygonal contour which may be given these cones.

The machine comprises a bed or base frame I 11 above which is supportedthe revolving cylinder 12. Four pairs of bearing blocks 13 rise fromthis bed, two pairs at each side thereof, and support the journal endsof four flanged rollers 14. Adjacent its ends, the cylinder 12 hassecured thereto circular treads or rings 15 which whereby the cylinderis supported for rotary motion. The flanges of the rollers 14; engage onthe inner sides of the tread rings 15, thereby holding the cylinderagainst endwise shifting movement.

Rising from the ends of the bed 11 are two bearing standards 16 and 17in which are journaled the ends of two blade supporting shafts 18 and 19which pass through the cylinder 12 adjacent the lower portion thereof.The right hand ends of these shafts (Fig. 1) are journaled in bearings21 mounted on the bearing standard 16, and the left hand ends arejournaled in spaced pairs of bearings 22 and 23 mounted on the oppositebearing standard 17. The two shafts are geared together for rotation inopposite directions by two spur gears 24 and 25, mounted on these shaftsin meshing relation between the pairs of bearings 22 and 23. These gearsare preferably enclosed in a suitable gear housing 26 supported betweenthe pairs of bearings 22 and 23. One of the shafts, preferably the shaft18, is extended beyond the endmost bearing 23 for mounting a drivingelement 27, such as a pulley or gear, through which driving energy istransmitted to the machine. Those portions of the two shafts 18 and 19which extend through the cylinder 12 may be of square or polygonalsection for mounting the blade units, as will be hereinafter described,and when thus constructed of polygonal section these shaft portions arepreferably made separable from the shaft ends which are journaled in thebearings 21, 22 and 23. Cooperating pairs of collars 28 and 29 may beprovided for joining the left hand ends of each of these polygonal shaftsections to the cylindrical shaft section, and clamping members 31 maybe employed for joining the right hand ends of these polygonal shaftsections to the cylindrical shaft ends which are journaled in thebearings 21.

The right hand end of the shaft 18 is extended beyond the right handbearing 21 for receiving a spur pinion 32 which meshes with a large spurgear 33. This large spur gear is mounted on a countershaft 34 extendingalongside the cylinder 12 and journaled in roll on the flanged rollers14;,

spaced bearings 35 and 36 mounted on frame extensions 37 and 38. Securedto the other end of this countershaft is a small sprocket wheel 39 overwhich tracks a. driving chain 41. This chain passes around a sprocketring 12 which is secured to the outer circumference of the cylinder 12,preferably at a point intermediate the tread rings 15.

It will be apparent that as a result of this driving relation betweenthe shafts and the cylinder, driving rotation imparted to the pulley 27in the direction indicated will result in rotation of the two shafts l8and 19 in opposite directions, and-in rotation of the cylinder 12 in a.counterclockwise direction as viewed in Fig. 2. V

Mounted on the shafts 18 and 19 at spaced points along their, lengthswithin the cylinder 12 are a plurality of paddles or mixing blade units44. As best shown in Figs. 2 and 1, these blade units each consists of ahub 15 fixedly mounted on the shaft. and oppositely extending blade arms46. WVhere the blade mounting portions of the shafts 18 and 19 are ofsquare or polygonal section, the hubs 15 are of corresponding form so asto be rigidly mounted on these shafts. As viewed from the end, (see Fig.2), the two blade arms project at an angle or non-radially relative tothe square hub 45 in a trailing direction or rearward with respect tothe direction of rotation of the shaft. In addition to having thisrearward non-radial angle, each blade is disposed helically relative toits hub so that it will have a feeding pitch for gradually feeding thematerial back through the cylinder along the bottom thereof. As shown inFig. 1, the blade units on one shaft are offset or staggered relative tothe blade units on the other shaft, so that the blade arms will cleareach other. These blade arms inscribe arcs of rotation which intersector overlap each other as viewed from the end, see F ig. 2. The bladeunits on the two oppositely rotating shafts have their blade armsoppositely ar ranged with respect to the trailing angle of inclinationand the helical pitch angle above described. Preferably, the two shafts18 and 19 are spaced equidistantly from a vertical axial plane passingthrough the axis of the cylinder, and the shafts are supported at theproper vertical height to space the blade ends from the inner wall ofthe cylinder, substantially as shown in Fig. 2. The blades may beprovided with holes 17 therein for receiving the bolts of supplementaryblades which can be bolted to the old blades when the edges of thelatter have worn down.

To remove any material tending to adhere to the side walls of thecylinder 12 there is provided a scraper 48 extending longitudinally ofthe cylinder from end to end thereof. This scraper is preferablypositioned to engage the inner wall of the cylinder at a pointapproximately above the shaft 18. The scraper is mounted on a shaft 49,the ends of which project beyond the ends of the cylinder 12 formounting in bearings 51 carried by a stationary frame structure 52embracing the ends of the cylinder. Arms 53 extending from the ends ofthis scraper shaft 49 support counterweights 5st which tend to hold thescraper pressed against the side wall of the cylinder. The scraperpreferably extends forwardly against the direction of rotation of thecylinder so that the action of shearing the material from the wall ofthe cylinderwill operate to press the scraper with greater pressureagainst this side wall.

The water for admixing with the ore is sprayed downwardly from anapertured spray pipe 56 extending longitudinally of the cylinderadjacent the upper part thereof. The volume of water projected throughthese downwardly opening spray apertures can be regulated by the controlvalve 57.

The ore is fed to the mixer through an inlet chute 58 which dischargesinto the right hand end of the cylinder. The hopper is supported in anysuitable manner, as by the framework 52 which supports the scraper a8,and at its lower end carries a circular end plate 59. The scraper shafta9 extends out through this stationary end plate 59 at this end of thecylinder. An inwardly extending closure ring 81 is secured to this endof the cylinder, being set outwardly from the end plate 59 to overlapthis plate, substantially as shown in Fig. 3, the two forming an endhead for this end of the cylinder.

The opposite end of the cylinder overhan 's a discharge hopper 62 whichhas a laterally flaring upper portion 63 embracing the sides of thecylinder at this discharge end, and a constricted lower portion 64 whichpasses down through an opening in the base frame 11. The outlet from thehopper may discharge to any suitable point, where the ore may be furthertreated, or conducted directly to the sintering apparatus. In theoperation of the device the ore is admitted at a predetermined ratethrough the feeding hopper 58, creating a bed of the material in thebottom of the cylinder in the zone of the blades. These blades, by theiropposite rotation in the directions indicated will tend to confine thismaterial in a pile in the lower part of the cylinder. ldoreover,'the twosets of blades, by rotating in the directions indicated, have the actionof throwing the material upwardly between the two shafts in a veritableshower of material, which falls baclr upon the blades and upon the sidesof the cylinder. The consequent agitation or stirring of the materialwill present new surfaces to the action of the water projected down fromthe overhead spray pipe 56. As the material becomes somewhat plastic orad hesive it will tend to adhere to the side walls of the cylinder,being carried up to the scrapspreading of the material laterally in theop A posite direction is defeated by the motion of the cylinder whichimmediately carries the material back into the zone of blade action. Notumbling of the material within the cylinder is desired, and thistumbling is avoided by rotating the cylinder at a relatively low speed.For example, 1 find a rotation of approximately one hundred andtwenty-five revolutions per minute as being sutliciently low to avoidthis tumbling action and still secure the necessary rate of return feedto the blades for greatest efficiency. The cylinder thus servesprimarily as a moving trough surface, preventing packing on the sidewalls thereof, and continuously rolling the material back into the zoneof blade action.

The action of the several blades on both shafts 18 and 19 is to feed thematerial progressively along the bottom of the cylinder simultaneouslywith their mixing action. The completely moistened and mixed material isfinally discharged over the outlet end of the cylinder into thedischarge hopper 62.

t may be desirable to employ only one shaft and its associated mixingblades, and in such instance this one shaft is disposed slightly to theright of the vertical axial plane of the cylinder, in the direction thatthe shaft 18 is removed from this vertical axial plane in Fig. 2.

In Figs. 5 to 8, inclusive, I have shown supplementary apparatus forballing the mixture after it has been mixed and moistened in thecylinder 12. Such balling of the sintering mixture into small sphericalaggregates tends to increase its speed of sintering in down draftsintering apparatus. However, before such balling operation is performedit is necessary or desirable that the materials be intimately mixed andmoistened. For example. if an ore of plastic nature were being mixedwith finely divided carbonaceous fuel, there would be a tendency for theore to agglomerate into large masses under the tumbling action of themixing or balling cylinder, which would prevent the thorough admixtureof the carbonaceous fuel therewith. However, by first mixing thematerials in the manner hereinbefore described, the required intimacy ofmixture of the fuel and ore is first obtained, whereupon the re sultantmixture, properly moistened, can be subjected to the desired ballingaction. By performing the steps in this manner the small globularaggregates are made of uniform Elli till

composition, which is desirable for the sintering operation.

Figs. 5 to 8. inclusive, are somewhat diagrammatic inasmuch as themixing cylinder 12 is not illustrated at its full length, al though insome instances it may be practicable to use a comparatively short mixingcylinder. Referring particularly to Fig. 5, the mixing cylinderdischarges into a rotating drum or chamber 66, preferably of conicalform. The blade units on the shafts 18 and 19 are not extended into thisballing drum, and hence the material precipitated into the drum is notsubjected to any further mixing thereby. In the embodiment disclosed inFig. 5, the balling drum is provided with tread rings 67 and 68 adjacentits ends, which tread rings track on rollers 69 and 71, similarly to themounting of the mixing cylinder 12. The discharging end of the mixingcylinder 12 extends a short distance into the smaller end of the ballingdrum 66. The large end of this balling drum can be arranged to dischargeinto a chute or receptacle, as desired. The balling drum is driven by achain 72 passing over a sprocket wheel 7 3 on the countershaft 3'4 andtracking over a sprocket ring 7% secured to the circumference of theballing drum. The balling drum may be. driven at a higher speed than themixing cylinder 12 to augment the tumbling and balling action of thematerial.

Fig. 6 illustrates the same general relation of balling drum and mixingcylinder. with the exception that in this embodiment the balling drum issecured directly to the end of the mixing cylinder so as to rotatetherewith. The outer end of the balling drum is preferably provided witha tread ring 68 rolling on rollers 71 to support this end of the drum.

In Fig. 7 the conical balling drum is extended backwardly over themixing cylinder 12. this affording a relatively short, compactconstruction. In this form the inner end of the mixing cylinder isprovided with extending arms which are fastened to a tread ring 76tracking on the rollers 77. The balling cone 66 is provided with treadrings 67 and 68' tracking on pairs of rollers 69 and 71'. In thisconstruction, the balling cone 66 is adapted for rotation independentlyof the mixing cylinder 12, and consequently, if desired, this ballingcone can be rotated at a higher speed through its sprocket chain 72. Thedischarge end of the balling cone may discharge into any chute orreceptacle below the mixing cylinder. In this instance the driving chain41 tracks over a sprocket ring 42 at the feed end of the cylinder.

In Fig. 8 the same general relation of mixing cylinder and balling coneis employed except that these two elements are connected together forsimultaneous rotation. Small angle brackets 81 may be secured betweenthe diseh arge end of the mixing cylinder and the small end of theballing cone. Likewise, larger brackets 82 may be secured between theinlet end of the mixing cylinder and the discharge end of the ballingcone. In this embodiment the drive is directly to the sprocket ring 74'encircling the outer circumference of the balling cone.

The action of the balling cone in each of the preceding embodiments isto carry a portion of the moistened material up along its side wall andto thereupon drop this material, allowing it to roll downwardly andagglomerate into spherical form. by adherence between the moistenedparticles. Simultaneously with this downward rolling motion of thematerial along the side walls of the cone,-the material is also rolledlongitudinally of the cone towards its larger end, which latter rollingmotion also assists in agglomerating the material into spherical form.The pitch of the cones is such that the action is automatic in that whenthe material has united in spheres of sufficient size these spheres orballs will roll down the. slope of the cone and discharge at the largeend thereof; while the material which has not been balled will have amuch slower rate of feed down the slope of the cone.

In Fig. 9 I have illustrated a polygonal formation which I may giveeither of the balling cones described in the preceding embodiments. Thispolygonal contour is advantageous in that it secures a more pronouncedballing action. This follows from .the fact that the mixture resting oneach surface of the polygon will rise to a certain angle, at which pointthe material will roll back over its surface. The finer, unballedportion will tend to cling to the polygonal surface at higher angles,with the result that the small aggregates rolling over such fine portionwill result in the fine portion tending to adhere thereto, therebyincreasing the size and degree of sphericity of such aggregates. Thispolygonal formation of balling cone, in particular, can be rotated athigher speed than the mixing cylinder, for securing effective balling ofthe mixture.

What I claim as my invention and desire to secure by Letters Patent, is

1. In m'xing apparatus, the combination of a troug member, a pair ofshafts having mixing blades thereon operating within said trough member,said shafts being rotated in opposite directions, and means for movingsaid trough member for confining the material within the radius ofaction of said blades.

2. In mixing apparatus, the combination of a horizontally disposedrotating cylinder, a pair of shafts disposed in said cylinder havingmixing surfaces thereon operating adjacent the bottom of said cylinder,said shafts lid being rotated in such directions as to cause thematerial being mixed to be thrown upwardly between said shafts, saidcylinder being rotated for confining the material within the radius ofaction of said mixing surfaces.

3. In mixing apparatus, the combination ofoa horizontally disposedcylinder. the lower portion of which defines a trough bottom, a pair ofshafts disposed on opposite sides of the vertical axia plane of thecylinder and having mixing blades thereon operating within said troughbottom, the blades on one shaft being staggered relative to the bladeson the other shaft, and means for rotating said shafts and saidcylinder.

4.. in mixing apparatus, the combination of a horizontally disposedcylinder, the lower portion of which defines a trough bottom, a pair ofshafts having mixing blades thereon operating within said trough bottom,the blades on one shaft being staggered relative to the blades on theother shaft, and means for rotating said cylinder and for rotating saidshafts in opposite directions, so as to cause the material being mixedto be thrown upwardly between said shafts.

5. ln mixing apparatus, the combination of a horizontally disposedrotating cylinder, the lower portion of which defines a trough bottom. apair of shafts having mixing blades thereon operating within said troughbottom, the blade units on one shaft having their blade arms oppositelyarranged with respect to the trailing angle of inclination of those onthe other shaft, means for rotating said cylinder and said shafts, saidshafts being rotated oppositely and in such directions as to cause thematerial to be thrown upwardly between said shafts, and a scraperoperating to remove material adhering to the inner wall of saidcylinder.

6. In mixing apparatus, the combination of a horizontally disposedcylinder, the lower portion of which defines a trough bottom, a pair ofshafts having mixing surfaces thereon operating within said troughbottom, means for rotating said shafts and said cylinder, a scraper forremoving material tending to adhere to the inner wall of said cylinder,and means for yieldably holding said scraper in operative position.

7. In mixing apparatus of the class described, the combination of acylinder disposed substantially horizontally, a plurality of supportingrollers, tread rings on the outer side of said cylinder tracking on saidrollers, a pair of shafts extending longitudinally within said cylinderand disposed on opposite sides of the vertical axial plane of saidcylinder, mixing blades on said shafts, the lower portion of saidcylinder defining a trough bottom for said mixing blades, means forrotating said shafts in opposite directions to cause the blades torevolve downwardly from the outer sides of said shafts towards saidtrough bottom, and a toothed member on said cylinder through whichdriving rotation is transmitted to said cylinder.

8. In mixing apparatus of the class described, the combination of a drumof generally cylindrical 'forrn disposed substantially horizontally,tread rings on said drum, supporting rollers on which said tread ringstrack, a pair of shafts extending longitudinally through said drum anddisposed on op- V posite sides of the vertical axial plane of said drum,mixing blades on said shafts operating adjacent the lower side of saiddrum, means for rotating said shafts oppositely and in such directionsas to cause said blades to revolve downwardly from the outer sides ofsaid shafts toward said axial plane, a countershaft operativelyconnected to one of said first shafts, a sprocket ring mounted on saiddrum, a sprocket on said countershaft, and a driving chain tracking oversaid sprocket and sprocket ring.

9. ln apparatus for preparing powdered or pulverized ores for sintering,the combination of a base, a horizontally disposed cylinder, supportingrollers mounted on said base, tread rings on said cylinder tracking onsaid rollers, means for feeding the ore into one end of said cylinder, apair of shafts extending through said cylinder, said shafts beingdisposed substantially in the same horizontal plane and being spacedsubstantially equidistantly from the vertical axial plane of saidcylinder, mixing blades mounted on both of said shafts and rotatingthrough overlapping arcs in proximity to the bottom of said cylinder, awater spray pipe extending longitudinally within said cylinder forspraying water on the material therein, and means for revolving saidshafts and cylinder, said shafts being revolved oppositely and in suchdirections as to cause the blades to throw the material upwardly betweensaid shafts.

10. In. apparatus for preparing ores for sintering, the combination of arotating cylinder disposed substantially horizontally, a pair of shaftsextending through said cylinder, each of said shafts comprising a shaftportion of polygonal cross-section disposed within the cylinder and ashaft portion of round cross-section extending co-extensively therefromfrom the end of said cylinder, mixing blades mounted on the twopolygonal shaft portions, bearings in which the rounded shaft portionsare journaled, collars on said co-extensive shaft portions for joiningthe same together, and means for rotating said cylinder and said shafts.

11. in apparatus for preparing ores for sintering, the combination of'arotating cylinder disposed substantially horizontally, a rotating shaftof polygonal cross-section extending through said cylinder, and mixingmembers mounted on said shaft for mixing the ore within said cylinder,each of said mixing members comprising a hub having a polygonal openingtherein for engaging nonrotatably on said shaft, and comprising bladesformed integral with said hub and extendin from diametrically oppositesides thereo each of said blades having a helical feeding pitch andprojecting non-radially from said hub in a trailing direction withrespect to the direction of rotation of said shaft.

12. In mixing apparatus, the combination 7 of a cylinder disposedsubstantially horizontally, rollers engaging tread surfaces on the outerside of said cylinder for rotatably supporting the latter, a pair ofshafts extending longitudinally within said cylinder and disposed onopposite sides of the vertical axial plane thereof, and mixing blades onsaid shafts, the arms of the blades inscribing arcs of rotation whichintersect or overlap each other, and which lie in close proximity to thebottom of the rotating trough defined in said cylinder, for actingdirectly on the material carried downwardly along the side of saidcylinder, said shafts being rotated oppositely and in such direction asto throw the material upwardly between the same. v

BETHUNE G. KLUGH.

